Hi, everyone I am a new user
I have a 2004 A4 3.0Q with 60k miles and I use high octane gas regularly. I just started noticing a vibration in the engine. The engine check light is NOT on so I can't read any codes with my OBD-II.The vibration happens even when I'm idling, so I know it's not related to axle or wheel problems. I changed the spark plugs and cleaned the air filter duct. Drove the car for 15 miles with no problem, then the vibration came back.Then I put some STP injector cleaner and again worked good forabout 15 miles... then vibration came back
I noticed that when the vibration comes if I rev the engine, I can feel air being sucked from the air filter (as if it had a cone) but I have a stock filter and box.
Today I'm putting in a new K&N filter... to see if the problem is the air filter.
Also, the fuel filter has never been changed.
Any help is much appreciated!
Nick

 

It could be that the mounts have to be replaced. Does the car idle up and then down when you're waiting at a light? Usually vibration will occur if:

[ul][*]Flywheel needs balancing[*]Crank shaft needs to be balanced (unlikely)[*]Motor mounts need to be replaced[/ul]
From what you're saying it sounds like the car is idling erratically and needs to be tuned or something. Clean out your mass airflow sensor (MAF) or you Throttle body. Try a TB reset and go from there.

TB reset

interesting thread about erratic idling



Good luck

 

I'm having the same problem bro - I have an 02 A4 1.8T (auto) and it vibrates when idling. In the last month I've replaced the motor mounts with street density 034 Motorsport mounts, APR front snub mount and a new front axle ... still vibrating when I'm idling.

I'm going to readjust the bracket on the snub mount - I heard if you don't have that just right it could cause some vibration. I know that with upgraded mounts and snub there will be some vibration, but the amount I'm getting just doesn't seem right.

 

i had the same issue and i just had a cracked inline check valve on my vacuum. it idled rough and was vibrating a bit. quick change of the valve from ecs and it was gone

just my 2 cents. good luck

 

you guys all have 18t w/ engine vibrating problems... this engine is notorious for every single vacuum line cracking... not one more than the other. all of them... before replacing motor mounts... check all your lines

 

and depending on which lines is broke will decided if it throws a code or not


and the 3.0.... plasticbreather hoses break

 

I just got my new inline check valve from ECS ... I'll be replacing that ASAP

 

[sm=signs003.gif]

 

What throws me off is that the vibration is not constant. Last time I drove the car, it ran good and after half an hour started vibrating, the whole car was shaking and on the way back from work it didn't vibrate at all but I felt a little loss of power.

Because the problem comes and goes I don't think it has anything to do with the flywheel, or the engine mounts (although If I keep driving it while it vibrates I might break them)

I guess I'm gonna look at the vacuum hoses. Hopefully they are all visible from the top w/o putting the car on a lift,

Thanks again for all your comments... keep'em coming!

-nick

 

Seriously bro, check that inline check valve if you haven't already ... mine looks pitiful. It's a wonder my car even starts.

Part number for www.ecstuning.com(Part #058 905 291)